This invention relates to a device for handling and positioning a socket core in a machine for the centrifugal casting of cast-iron pipes.
Such a machine of known type comprises a chill-mould mounted to rotate in a casing provided with cooling means and a gate. The gate is able to traverse the entire length of the mould interior to pour molten cast iron therein during the course of a relative translational movement between the machine casing and the gate.
The chill-mould which defines the external shape of the cast-iron pipe receives a core at one end to define the internal shape of the pipe socket. The core is made of moulding-sand, and is replaced after each casting operation. It is brought forward and positioned at the end of the mould by a handling and positioning support device to which the invention relates.
French Pat. No. 2,314,790 discloses a support device for handling and positioning a socket core at the end of a chill-mould for centrifugal casting, which is pivoted on a horizontal shaft supported by the casing of the machine and which may rotate about this shaft between an upper retracted position above the socket end of the mould and a lower position for the introduction of the core into the mould.
This support device comprises two parts, both mounted to rotate about the same horizontal shaft under the opposing actions of a jack and a counterweight: a core support proper which is retracted in an upwards direction at the time of casting and a support member which is retracted in an upwards direction in order to receive a new core but which remains in the lowered position supporting the core axially inside the chill-mould during casting.
This device requires the operator to position a new core on the support in the upwardly retracted position, and provides good visibility inside the socket of the chill-mould during casting. It is perfectly suitable for relatively light cores of small diameter (for example less than 300 mm) which an operator can easily place into position on the support in its upper position without excessive fatigue.
On the other hand, for diameters greater than 300 mm the cores become relatively heavy, which makes it arduous for an operator to repeatedly position the core on the support in its upper position a great number of times during a working shift.